Sylvie Cauville of the Centre for Computer-aided Egyptological Research at Utrecht University and Eric Aubourg dated it to 50 BC through an examination of the configuration it shows of the five planets known to the Egyptians, a configuration that occurs once every thousand years, and the identification of two eclipses. The solar eclipse indicates the date of March 7 51 BC, it is represented by a circle containing the goddess Isis liking an animal (wild boar) by the tail. The lunar eclipse indicates the date of September 25 52 BC, it is represented by an Eye of Horus locked into a circle. Source